000 AXPZ20 KNHC 300900 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 612 UTC Sat Sep 30 2017 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0900 UTC. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends across Central America to a 1007 MB low pres near 15N95W to 1010 MB low pres near 12N111W to 10N122W to 1011 MB low pres near 12N132W to 11N140W. Scattered moderate isolated strong convection was noted north of 14N between 94W and 99W. Scattered moderate convection was noted from 09N to 11N between 111W and 120W. Scattered moderate isolated strong convection was noted from 11N to 13N between 131W and 134W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gap winds will freshen over the Gulf of Tehuantepec the next couple of night. Elsewhere, a ridge will dominate the waters west of the Baja California Peninsula producing gentle to moderate northerly winds and seas of 4-5 ft today. Northerly swell will propagate into the waters west of Baja California Norte late this weekend, building seas to 6-8 ft by early next week. Fresh to locally strong S-SW winds are expected over the northern Gulf of California Sunday night through Tuesday as low pressure develops over the area. Seas are forecast to build to 5-6 ft with these winds. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... An active monsoon trough is currently across Central America and adjacent waters. The trough will remain close enough to the coast, either inland or just offshore, to produce active convection, primarily during the late afternoon and evening hours, over portions of Central America as well as the adjacent coastal waters during the next few days. Winds will begin to increase south of the monsoon trough this weekend. Long period SW swell will propagate across the offshore waters with seas of 5-7 ft through the weekend. Looking ahead, a broad area of low pressure developing over Central America will cause monsoonal winds to surge to fresh to strong speeds west of Costa Rica from Sunday night through at least the middle of next week. Seas of 8 ft or higher will affect the waters beyond 200 nm off the coast from Nicaragua to Guatemala. A fresh SW swell train, with a leading edge period of 20 to 22 seconds is forecast to reach the waters between Ecuador and the Galapagos Islands Tuesday night, building seas to 7-8 ft by Wednesday night. REMAINDER OF THE AREA... A ridge extends from 1022 mb high pressure located near 32N135W to near 23N114W. The pressure gradient between the ridge and the monsoon trough is supporting gentle to moderate winds. The high pressure is forecast to remain nearly stationary over the next 24 hours. Northerly swell will propagate into the waters north of 25N between 120W and 130W Sun through Mon night, building seas to near 12 ft along 30N by Monday. Farther south, cross equatorial southerly swell will propagate across the waters south of 02N between 105W and 135W by Tuesday, with seas building to 8-10 ft. $$ AL